retrievals of dayside emission spectra: trends in chemistry michael line, aaron wolf, xi zhang, yuk...
TRANSCRIPT
![Page 1: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/1.jpg)
Retrievals of Dayside Emission Spectra: Trends in Chemistry
Michael Line, Aaron Wolf, Xi Zhang,Yuk YungCaltech
![Page 2: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/2.jpg)
Thermo. Eq.
Vertically Mixed
Photochemistry
Ions
CO
CH4
CO quenched
CH4 quenched
![Page 3: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/3.jpg)
€
fH2O fCH4fCO fH2
3 P 2=Keq
H2O + CH4 = CO + 3H2
![Page 4: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/4.jpg)
Synthetic Study
S/N~3.5Δλ=0.0075 μm
Spitzer Broadband Spitzer Broadband+IRS+NICMOS
FINESSE
![Page 5: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/5.jpg)
MCMC
Optimal Est.
![Page 6: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/6.jpg)
HD189733Moses et al. 2011
WASP12Kopparapu et al. 2012
GJ436Line et al. 2011
![Page 7: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/7.jpg)
GJ436
HD189733
TRES2
HD149026
WASP19 WASP12
HD189733Moses et al. 2011
WASP12Kopparapu et al. 2012
GJ436Line et al. 2011
![Page 8: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/8.jpg)
GJ436
HD189733
TRES2
HD149026
WASP19 WASP12
MCMC
OPT. EST.
Dis-eq. Models
HD189733Moses et al. 2011
WASP12Kopparapu et al. 2012
GJ436Line et al. 2011
![Page 9: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/9.jpg)
Conclusions
• Opt est and MCMC agree for “quality” data
• Most planets seem out of equilibrium (to within “1-sigma”)
• Errors large on current gas estimations
• Need dedicated space based spectroscopic instrument
• Can maybe constrain Kzz
![Page 10: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/10.jpg)
Goals
• Look at the ensemble of planetary atmospheres. Indentify trends in composition—equilibrium vs. disequilibrium
• First must robustly determine temperatures and compositions of exoplanet atmosphere
![Page 11: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/11.jpg)
Two Bayesian Retrieval Approaches
€
P(T,f |Data)∝ P(Data |T,f) × P(T,f)Optimal Estimation
(Lee et al. 2011 , Line et al. 2012)
This Parameter
That
Par
amet
er
€
χ 2
-Levenberg-Marquardt to find best solution
-Assumes Gaussian posterior
- Fast—not slowed down by additional parameters or more sophisticated forward models
This Parameter
That
Par
amet
er
€
χ 2
- Randomly explore’s all of parameter space
- Accounts for non-Gaussian posteriors
- Slow—many parameters and more sophisticated forward models unwieldy
Markov Chain Monte Carlo(Madhusudhan et al. 2011 , Benneke & Seager 2012)
Forward Model: [T, fH2O, fCH4, fCO ,fCO2]
Guillot 2010 [γv1, γv2, κIR, α, β]
![Page 12: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/12.jpg)
Synthetic StudySpitzer Broadband Spitzer Broadband+IRS+NICMOS
FINESSE
MCMCOpt. Est.True
![Page 13: Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech](https://reader035.vdocuments.site/reader035/viewer/2022062407/56649f525503460f94c75fdf/html5/thumbnails/13.jpg)
Synthetic StudySpitzer Broadband Spitzer Broadband+IRS+NICMOS
FINESSE